Device for fastening a pattern plate to a mold table or box

ABSTRACT

A pattern plate is releasably fastened to a mold table or box of a molding machine in a locally fixed position by extending a guide or locating pin through a suitably dimensioned and located guide hole in the pattern plate, and providing a cam follower riding on a helicoidal surface provided on or coacting with one of the two parts to be fastened to each other. Turning of the cam follower and the helicoidal surface relative to each other causes pulling of the table or box and of the pattern plate against each other.

ited States Patent Eibe 1 Ma 23 1972 DEVICE FOR FASTENING A PATTERN References Cited PLATE TO A MOLD TABLE OR BOX UNITED STATES s Inventor: Helm! Eibe. Offenbach am Main, 760,105 5/1904 Cunningham ..l64/386 many [73] Assignee: Roland Offsetmaschinenfabrik Faber & FOREIGN PATENTS OR APPLICATIONS Schlelcher AG, Ofienbach am Main, Ger- 1,159,135 12/1963 Germany ..l64/24l many Primary ExaminerRobert D. Baldwin [22] June 1970 Anomey-Hane, Baxley & Spiecens [2]] Appl. No.1 42,842

[57] ABSTRACT [30] Foreign Application Priority Data A pattern plate is releasably fastened to a mold table or box of a molding machine in a locally fixed position by extending a June 4, 1969 Germany ..P 19 28 362.6 guide or locating pin through a Suitably dimensioned and located guide hole in the pattern plate, and providing a cam [if] 3! "164/2416; follower riding on a helicoidal surface provided on or coacting E f 349/165 with one of the two parts to be fastened to each other. Turning 349/166 of the cam follower and the helicoidal surface relative to each other causes pulling of the table or box and of the pattern plate against each other.

14 Clains, 1 1 Drawing figures PATENTEUMAY 23 972 SHEET 1 OF 2 FIG.

FIG. 4

FIG. 3

A T TU/CNE m DEVICE FOR FASTENING A PATTERN PLATE TO A MOLD TABLE OR BOX The invention relates to a device for releasably fastening a pattern plate to a mold table or box of a molding machine, and more particularly to a fastening device of the general kind above referred to in which at least one locating or guide pin extending from the mold table or box normal to a supporting surface thereof, coacts with a corresponding guide in the pattern plate.

BACKGROUND It is generally accepted in the molding industry that a pattern plate must be fastened to a mold table or box in an accurately fixed position and safely held in such position. There are known devices for the purpose in which the pattern plate is located by one or several guide pins and is locked in position by suitably arranged screw connections. Such screw connections are capable of sustaining strong forces as may occur, particularly with pressure operated molding machines. However, loosening of the screw connections for the purpose of exchanging the pattern plate is comparatively time-consuming so that frequent exchanges of the pattern plate as is often necessary, entail high labor costs, especially when the molding run is fairly small.

There are also known magnetically operated fastening devices. Such devices can be conveniently and fairly rapidly operated, but often require more space than is generally available.

THE INVENTION I referred to which requires only two basic parts which can be conveniently tightened in fixed relative positions and can be equally conveniently and rapidly released.

SUMMARY OF THE INVENTION The aforepointed out objects, features and advantages, and other objects, features and advantages which will be pointed out hereinafter, are obtained by providing a cam follower in the form of a bar which protrudes from the wall of a guide or locating pin and rides on a helicoidal surface after the pin is inserted into guide holes within the pattern plate and the table or box-shaped support to be fastened to each other. Turning the bar and the helicoidal surface, which constitutes a camming surface, in one circumferential direction relative to each other causes the bar to ride up on the same, thereby pulling the pattern plate and the mold plate or box toward each other, and turning of the bar in opposite circumferential direction releases the two parts from each other. Turning of the helicoidal surface and the bar relative to each other may be effected by turning the bar, which is disposed normal to the lengthwise axis of the pin, about an axis also constituting the center axis of the helicoidal surface and the pin. As it is evident, the result of such turning of the bar is a relative movement in axial direction of the part bearing the helicoidal surface and of the part mounting the bar, and it is this relative movement which is utilized to obtain the desired movement of the pattern plate and the mold table or box toward each other. As it is also evident, the same result can be obtained by turning the helicoidal surface. In either case, the pitch angle of the helicoidal surface should be such that self-locking of the two parts rotated relative to each other is assured.

The device of the invention as described is very space saving as the guide pins which must be provided in any event for carrying out the molding operation, as previously explained, are simultaneously used for fastening the pattern plate and in fact constitute an essential component of the device according to the invention.

Operation of the device, namely rotating the bar through an angle, for instance of 30", is extremely simple and timesaving.

According to one aspect of the invention, the helicoidal surface is provided on the pattern plate, thereby making unnecessary a reduction of the cross-section of the guide pin. Of course, the helicoidal surface may also be provided on the guide pin itself.

According to another aspect of the invention, one end of the guide pin is fixedly secured to the mold table or box and has cut-outs or slots in its wall. The bar is journaled within the then hollowguide pin and rotatable in a plane substantially normal to the axis of the pin, the rotational angle of the bar being limited by the width of the cut-outs or slots. Such an arrangement permits turning of the bar even though the guide pin is fixedly secured to the mold table or box. A fixed mounting of the guide pin greatly improves the guidance thereof and assures accurate guiding even after the device has been used for a considerable length of time.

The invention also provides that the helicoidal surface is formed on the crosswise surfaces of the pin wall defining the slots therein.

The invention further provides an arrangement in which a pinion is rotatable within the pin coaxial therewith. One end of the pinion protrudes from one end of the pin and has preferably the shape of a polygonal head. This permits convenient rotation of the bar by means of a key or wrench fitting the head.

The invention further contemplates to provide on the end of the pinion protruding from the pin a collar or flange which has approximately the same outer diameter as the pin. This collar or flange constitutes in effect a continuation of the pin and protects the bearing constituted by the pinion against the ingress of dirt or moisture. Preferably, a scaling is additionally interposed between the pin and the collar or flange.

The helicoidal surface may bein the form of a suitably shaped groove in a surface of a guide sleeve fitted into the holes of the pattern plate and/or the mold table or box. Such an arrangement results in a particularly compact structure of the fastening device. The helicoidal surface and the cross-bar are concealed when the device is fully assembled and thus protected against the ingress of dirt and moisture.

A guide for the pin may be formed by a guide sleeve or bushing secured to the pattern plate. As the pattern plate is often made of a synthetic plastic while the guide sleeve is advantageously made of metal, the use of such guide sleeve offers advantages in the manufacture of the parts, as it is apparent.

The invention also includes a device in which the helicoidal surface is provided on the guide sleeve and the sleeve is rotatable relative to the bar. The sleeve is advantageously provided with recesses or protrusions for engagement by a tool suitable for rotating the sleeve. Such an arrangement permits to design the pin and the cross-bar as a single component which may be secured on the mold table or box.

DETAILED DESCRIPTION OF THE INVENTION In the accompanying drawing several embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

FIG. 1 is an elevational sectional view of a fastening device according to the invention;

FIG. 2 is an elevational sectional view of the device of FIG.

.1 as seen in the direction of arrow 11;

FIG. 3 is a sectional elevational view of a modification of the device;

FIG. 4 is a sectional elevational view of another modification of the device;

FIG. 5 is a simplified plan view of FIG. 3;

FIG. 6 is an elevational sectional view of still another modification of the device;

FIG. 7 is an elevational view of FIG. 6 turned through FIG. 8 is an edge view of the helicoidal surface of the device and the bar-shaped cam follower riding on the surface on an enlarged scale;

FIG. 9 is a perspective view of the helicoidal surface of FIG.

FIG. 10 is an edge view of a modification of the helicoidal surface; and

FIG. 11 is a perspective diagrammatic view of a pattern plate secured to a table-shaped mold box.

Referring now to the figures more in detail, the fastening device as exemplified in FIGS. 1 and 2 comprises a support member 2 in the form of a table upon which a pattern plate I (see FIG. 11) is to be secured in a predetermined position relative to the table. To locate the pattern plate on the table a guide pin 3 (or several pins) is fixedly secured in a threaded bore 30 of table 2 by suitable fastening means, such as a nut 35. The guide pin extends through a guide hole 4 in pattern plate 1. This guide hole is defined by a guide sleeve or bushing 5 which is suitably secured to plate 1 as by screws or other fastening means.

The guide pin is shown to be hollow and a cam follower in the form of a bar 6 extends through the pin normal thereto. The ends 7 of the cam follower protrude through slots 8 in the wall of the pin. The bar is rotatable about the center axis of pin 3 by means of a pinion 9 which itself is rotatable within the pin and fixedly secured to cam follower 6; the turning angle of the cam follower relative to pin 3 is limited by the width of cutouts or slots 8.

As is shown in FIGS. 1 to 3, pattern plate 1 is secured to table 2 by placing it from above about the table of a molding machine (not shown) so that guide pin 3 enters guide opening 4 thereby locating the pattern plate on the table. Cam follower 6 thus enters a slot 10 provided in pattern plate 1 or in guide sleeve 5.

The helicoidal surface defines a camming surface which extends through 360, or as shown in FIGS. 8 and 9, two camming surfaces each extending through an angle of about 180 may be provided, the two camming surfaces then defining therebetween a step 11a. Cam follower 6 is fully shown in FIG. 8 and indicated in FIG. 9 by a dash-dotted line.

As is clearly shown in FIGS. 1, 2 and 3, the end portions 7 of the cam follower are in engagement with the helicoidal surface. The cam follower coacts with this surface when rotated by means of pinion 9 about an axis which is coaxial with the lengthwise axis of pin 3. The pinion protrudes with its free end 12 from the open end 13 of pin 3 and is preferably enlarged to form a polygonally such as hexagonally shaped head 14 so that the pinion and with it cam follower 6 can be conveniently rotated by means of a conventional wrench.

A sealing ring 15 may be interposed between head 14 and end 13 of pin 3 to prevent ingress of mold sand into the bearing formed by pinion 9 for pin 3.

FIG. 3 shows a simplified structure of the fastening device according to the invention in that cam follower 6 is directly secured to pin 3 which may be solid in this case. The pin can thus be rotatably mounted in table 2. Axial displacement of the pin relative to the table is prevented by a bolt head 16 and a collar 18 secured to pin 3 by a screw 17 or other suitable means such as a rivet.

Helicoidal surface 11 and slot 10 for cam follower 6 components which perform the same functions are designated in all embodiments by the same reference numerals are machined directly into the pattern plate 1. To simplify manufacture, the helicoidal surface is not formed on an inside surface of the pattern plate, but on an outwardly facing side thereof, as it is clearly shown in FIG. 3. Such arrangement requires that slot 10 extends through the entire thickness of the pattern plate (see FIG. 5). As the guide pin 3 itself must be turned, the free end 13 thereof is given a polygonal peripheral outline.

FIG. 4 shows another simplified structure in which pin 3 is fixedly threaded into table 2, but cam follower 6 is nevertheless fixedly supported by pin 3. The helicoidal surface 11 is formed on a guide sleeve 19 which in contradistinction to the guide sleeve 5 of FIGS. 1 and 2 is rotatable relative to pattern plate 1. Accordingly, the camming surfaces constituted by helicoidal surface 11 are turned relative to the now stationary cam follower.

Recesses 20 in a flange of rotatable sleeve 19 permit convenient rotation of the sleeve by a tool suitable and conventional for the purpose. Sleeve 19 may be journaled in a bushing 21 fixedly mounted in the pattern plate.

As it is evident from the previous description, various kinetic reversals of the functions of the described and illustrated components may be provided within the scope of the inventive concept. For instance, provision of a helicoidal surface in FIGS. 1 and 2 on guide pin 3 instead of on guide sleeve 5 would not in any way change the operation of the device. The helicoidal surface may, for example, be machined into the upper or lower surface 22 defining the lengthwise ends of slots 8. FIG. 2 indicates such an arrangement. This figure also shows a groove 23 which is machined into sleeve 5 and defines at least at its upper side the helicoidal surface 11. With such arrangement, a relative movement between cam follower 6 including its pinion 9 and guide pin 3 would occur in the direction of the axis of the pin. The use of a sealing such as sealing 15 is particularly advisable in an arrangement of this kind.

Especially in the embodiments according to FIGS. 3 and 4, the helicoidal surface may be formed on the wall of pin 3 and cam follower 6 could be fixedly secured to pattern plate 1 (see FIG. 4).

The function of the device is also not changed when the helicoidal surface is provided on the outside of guide hole 4 (see FIG. 3), and also within the guide 4 (see FIG. 1).

In the event the cam follower is accessible from the outside, as it is shown in FIG. 3, the end 12 of pinion 9 need not to protrude from the pin (as it is shown in FIG. 1 as the cam follower can be directly gripped by a suitable tool.

According to FIGS. 6 and 7, pattern plate 1 is first placed upon the table or box-shaped support member 2; then pin 3 is fitted into a guide hole 24 in table 2. Pin 3 mounts cam follower 6 which extends through a slot 25 in table 2 and coacts with a helicoidal surface 11b. This surface defines a doubly curved camming surface, as it is indicated in FIG. 10. Of course, a camming surface such as shown in detail in FIGS. 8 and 9 may also be used, and vice-versa; the camming surface of FIG. 10 may be provided for the structures shown in FIGS. 1 to 5. It is formed on a generally ring-shaped member 26 suitably secured, for instance, by bolts 32 to outside of table 2.

Pin 3 has secured thereto a collar 27. Moreover, sleeves or bushings 28 and 29 are slidable on the pin. Sleeve 28 is located in guide hole 4 of pattern plate 1 and a spring element 30, diagrammatically indicated in FIGS. 6 and 7, is interposed between collar 27 and sleeve 29. Pin 3 terminates in preferably polygonal head 14 so that the pin can be conveniently turned by a suitable tool.

Collar 27, sleeve 29 and spring member 30 are disposed within a recess 31 of pattern plate 1. Moreover, the spring member biases pin 3 upwardly as sleeve 29 rests against the base of recess 31. As is now apparent, guide hole 24 in table 2 and guide hole 4 in pattern plate I automatically are moved into registry when pin 3 and sleeve 28 are pushed into the holes. As is further evident, rotation of pin 3 and with it of cam follower 6 will clamp the table and the pattern plate against each other between the cam follower and sleeve as the distance between the cam follower and the sleeve is reduced when the cam follower rides up on the camming surface.

FIG. 11 shows the mold support member 2 in the form of a mold table. Pattern plate I is secured thereto by means of a fastening device of the kind previously described. It may be pointed out in this connection that the length of guide or locating pin 3 is selected in accordance with the specific type of molding machine in conjunction with which the device is used.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

l. A device for releasably fastening a pattern plate upon a support member in the form of a mold box or table, said device comprising in combination:

a pattern plate member and a plate-shaped support member for said pattern plate member, at least said pattern plate member having an opening for inserting thereinto a locating pin to retain the two members in a predetermined superimposed position;

a locating pin member extending from the support member normal thereto and engageable with the opening in the pattern plate member, said pin member being restrained against axial displacement relative to the support member;

a wall portion including a helicoidally shaped surface and secured to one of said members;

a bar including at least one portion protruding crosswise from said pin member, said protruding bar portion coacting with said helicoidal surface for riding thereon; and

a pinion which is rotatable within said pin member,

rotation of said pin member and thus of said bar and of the helicoidal surface relative to each other causing the pattern plate member and the support member to be axially displaced against each other;

said locating pin member being a hollow member releasably secured at one end to the support member and having slots in its wall;

said bar being mounted on said pinion normal to the axis of the pinion and extending through said slots for coaction with said helicoidal surface, the crosswise width of said slots limiting the turning angle of the bar relative to the helicoidal surface.

2. The device according to claim 1 wherein said pinion protrudes from the outside of the pattern plate member for applying a turning force to the pinion and thus to the bar.

3. The device according to claim 1 wherein said helicoidal surface defines a camming surface extending through substantially 360, said protruding bar portion riding on said surface as the bar and the surface are rotated relative to each other.

4. The device according to claim 3 wherein said camming surface is divided into several circumferentially elongate sections, each section including a slanted surface portion.

5. The device according to claim 1 wherein said helicoidal surface comprises camming surfaces having circumferentially elongate rising and declining curved portions.

6. The device according to claim 1 wherein said helicoidal surface is disposed within said opening of the pattern plate and said bar is also disposed within said opening.

7. The device according to claim 1 wherein said helicoidal surface is formed on the pin member.

8. The device according to claim 7 wherein said helicoidal surface is provided on one of the crosswise surfaces defining the lengthwise ends of the slots in the pin member.

9. The device according to claim 1 wherein said helicoidal surface is provided on the outside surface of the pattern plate member.

10. The device according to claim 1 wherein said helicoidal surface is supported by the support member facing outwardly.

11. The device according to claim 1 wherein a guide sleeve is fitted into said opening of the pattern plate member, said guide sleeve guiding the locating pin member.

12. The device according to claim 11 wherein said helicoidal surface is formed on the guide sleeve.

13. The device according to claim 12 wherein said guide sleeve is rotatable within the opening of the pattern plate member, and the pm member mounting the bar rs supported by the support member secured against rotation and axial displacement relative thereto.

14. The device according to claim 1 wherein said helicoidal surface is supported by the support member facing outwardly, and wherein said pin member with the bar thereon is axially displaceable relative to the support member but restrained against such displacement relative to the pattern plate member. 

1. A device for releasably fastening a pattern plate upon a support member in the form of a mold box or table, said device comprising in combination: a pattern plate member and a plate-shaped support member for said pattern plate member, at least said pattern plate member having an opening for inserting thereinto a locating pin to retain the two members in a predetermined superimposed position; a locating pin member extending from the support member normal thereto and engageable with the opening in the pattern plate member, said pin member being restrained against axial displacement relative to the support member; a wall portion including a helicoidally shaped surface and secured to one of said members; a bar including at least one portion protruding crosswise from said pin member, said protruding bar portion coacting with said helicoidal surface for riding thereon; and a pinion which is rotatable within said pin member, rotation of said pin member and thus of said bar and of the helicoidal surface relative to each other causing the pattern plate member and the support member to be axially displaced against each other; said locating pin member being a hollow member releasably secured at one end to the support member and having slots in its wall; said bar being mounted on said pinion normal to the axis of the pinion and extending through said slots for coaction with said helicoidal surface, the crosswise width of said slots limiting the turning angle of the bar relative to the helicoidal surface.
 2. The device according to claim 1 wherein said pinion protrudes from the outside of the pattern plate member for applying a turning force to the pinion and thus to the bar.
 3. The device according to claim 1 wherein said helicoidal surface defines a camming surface extending through substantially 360*, said protruding bar portion riding on said surface as the bar and the surface are rotated relative to each other.
 4. The device according to claim 3 wherein said camming surface is divided into several circumferentially elongate sections, each section including a slanted surface portion.
 5. The device according to claim 1 wherein said helicoidal surface comprises camming surfaces having circumferentially elongate rising and declining curved portions.
 6. The device according to claim 1 wherein said helicoidal surface is disposed within said opening of the pattern plate and said bar is also disposed within said opening.
 7. The device according to claim 1 wherein saiD helicoidal surface is formed on the pin member.
 8. The device according to claim 7 wherein said helicoidal surface is provided on one of the crosswise surfaces defining the lengthwise ends of the slots in the pin member.
 9. The device according to claim 1 wherein said helicoidal surface is provided on the outside surface of the pattern plate member.
 10. The device according to claim 1 wherein said helicoidal surface is supported by the support member facing outwardly.
 11. The device according to claim 1 wherein a guide sleeve is fitted into said opening of the pattern plate member, said guide sleeve guiding the locating pin member.
 12. The device according to claim 11 wherein said helicoidal surface is formed on the guide sleeve.
 13. The device according to claim 12 wherein said guide sleeve is rotatable within the opening of the pattern plate member, and the pin member mounting the bar is supported by the support member secured against rotation and axial displacement relative thereto.
 14. The device according to claim 1 wherein said helicoidal surface is supported by the support member facing outwardly, and wherein said pin member with the bar thereon is axially displaceable relative to the support member but restrained against such displacement relative to the pattern plate member. 